Recently, Organic Light-Emitting Diode (OLED) elements have been developed toward large-area, thin-type and flexible substrate. However, the OLED elements are a kind of polycrystalline semiconductor being prone to be affected by oxygen or moisture, thereby resulting in the deterioration of the OLED elements. Therefore, the OLED elements need to be externally encapsulated so as to prevent influx of ambient gas.
The common encapsulation methods applied to OLEDs are the glass-frit technique and the “dam & filling” technique. The glass-frit technique is capable of resisting oxygen or moisture, but is not suitable for the large-area, thin and flexible elements. The dam & filling technique is not only capable of resisting oxygen or moisture, but also has high mechanical strength for encapsulation, but that technique is complicated and is not suitable for the large-area or roll-to-roll process.
Based on the above, the development of a novel encapsulating material applied to the encapsulation of large-area, thin-type and flexible OLEDs is urgent without delay.